Any vaccination can cause these symptoms which is why they usually advise to give calpol after vaccinations but if you are worried I would call NHS Direct/consider calling doctor out. Hope your lo gets better soon. By the way - not sure about swelling. Is it the whole arm or raised injection site? That sounds concerning imo.

Like he has a super muscle thing going on. Will see how he is in morning. Can't be bothered to wait the 3 hours for NSH direct to get back. He has gone back to sleep (pinched my single bed though) and will try to join him. Its intersting as he hasn't reacted to any of his other jabs